Traction is widely used to relieve pressure on inflamed or enlarged nerves. While traction is applicable to any part of the body, cervical and lumbar or spinal traction are the most common. When correctly performed, spinal traction can cause distraction or separation of the vertebral bodies, a combination of distraction and gliding of the facet joints, tensing of the ligamentous structures of the spinal segment, widening of the intervertebral foramen, straightening of spinal curvature and stretching of the spinal musculature. Depending on the disorder being treated, the traction component of physical therapy may require multiple sessions per week for a prolonged period of time.
U.S. Pat. No. RE 32,791 (Saunders) discloses a cervical traction device that includes a pair of v-shaped adjustable arms that grip the rear area of the patients head approximate the occipital bone and mastoid processes. The lateral separation between the v-shaped arms is adjustable to fit various size patients. The v-shaped arms grip the rear of the patient's head while leaving the mouth and jaw of the patient unrestricted. The cervical traction device of RE 32,791 is utilized on a conventional traction table, presumably under the care of a physician or a physical therapist. It is the physical therapist or other healthcare provider that adjusts the lateral separation of the v-shaped arms to fit the patient and correctly positions the patient relative to the cervical traction device.
With the advent of portable and in-home traction devices, patients perform traction therapy without the direct supervision of a healthcare provider. A low cost portable cervical traction device powered by a pneumatic cylinder that utilizing v-shaped adjustable arms generally disclosed in RE 32,791 is disclosed in WO 96/14810 (Saunders). The lateral position of the v-shaped neck supports is adjusted by the patient by turning left and right knobs coupled to a threaded shaft.
For portable or in-home traction devices to be safe and effective, the patient must properly adjust the lateral separation of the v-shaped neck supports and properly position his/her body relative to the cervical traction device. Moreover, since the shape of the occipital region varies from patient to patient, even properly adjusted neck supports can create uncomfortable locations of high pressure on the patients occipital region. Additionally, the lateral adjustment mechanism for the v-shaped neck supports adds considerable costs to the overall traction device. Consequently, what is needed is a self-seating occiput wedge system for cervical traction devices that also eliminates the cost of a mechanism for adjusting the lateral separation between the occiput wedges.